L1 : y=3x+50
L2 : y=6x-10
in order to find the value of x at the intersection point, it means that both lines will satisfy the value of y at this point. so that we can equalize the two equations and find the value of x as following:
3x + 50 = 6x - 10 (by subtracting 3x from both sides)
3x - 3x +50 = 6x -3x -10
50 = 3x -10 (by adding 10 to both sides)
50 + 10 = 3x -10 +10
3x = 60 (by dividing both sides by 3)
x = 20
